Patent Document 1 describes a gallium nitride-based semiconductor device having a gallium nitride-based semiconductor layer with good crystal quality. The gallium nitride-based semiconductor layer is provided on a main surface of the gallium nitride support substrate of the semiconductor light-emitting device. An angle (referred to as an off-angle) is formed between a line normal to the main surface of the gallium nitride support substrate and the C-axis of the gallium nitride support substrate. As the off-angle of the gallium nitride support substrate nears 0°, protrusions having the shape of a hexagonal pyramid are more often seen on the surface of the gallium nitride-based semiconductor layer. The angle is preferably less than 2°.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2005-159047